start work on Chapter 7

Chapter07/Cargo.toml

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+[package]
+name = "Chapter7"
+version = "1.0.0"
+
+[dependencies]
+
+[[bin]]
+name = "functor_pattern"
+path = "functor_pattern.rs"
+
+[[bin]]
+name = "monad_pattern"
+path = "monad_pattern.rs"
+
+[[bin]]
+name = "combinator_pattern"
+path = "combinator_pattern.rs"
+
+[[bin]]
+name = "lazy_pattern"
+path = "lazy_pattern.rs"

Chapter07/combinator_pattern.rs

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+
+fn main() 
+{
+}

Chapter07/functor_pattern.rs

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+use std::collections::{HashSet};
+
+fn main()
+{
+   let m: Vec<u64> = vec![1, 2, 3];
+   let n: Vec<u64> = m.iter().map(|x| { x*x }).collect();
+   println!("{:?}", m);
+   println!("{:?}", n);
+
+   let mut a: HashSet<u64> = HashSet::new();
+   a.insert(1);
+   a.insert(2);
+   a.insert(3);
+   a.insert(4);
+   let b: HashSet<u64> = a.iter().cloned().map(|x| x/2).collect();
+   println!("{:?}", a);
+   println!("{:?}", b);
+
+   let sentences = vec!["this is a sentence","paragraphs have many sentences"];
+   let words:Vec<&str> = sentences.iter().flat_map(|&x| x.split(" ")).collect();
+   println!("{:?}", sentences);
+   println!("{:?}", words);
+
+   let v: Vec<u64> = vec![1, 2, 3];
+   let s: HashSet<u64> = v.iter().cloned().map(|x| x/2).collect();
+   println!("{:?}", v);
+   println!("{:?}", s);
+}

Chapter07/lazy_pattern.rs

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+
+fn main() 
+{
+}

Chapter07/monad_pattern.rs

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+
+fn main() 
+{
+}